1# inline.m4 serial 4
2dnl Copyright (C) 2006, 2009-2020 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7dnl Test for the 'inline' keyword or equivalent.
8dnl Define 'inline' to a supported equivalent, or to nothing if not supported,
9dnl like AC_C_INLINE does.  Also, define HAVE_INLINE if 'inline' or an
10dnl equivalent is effectively supported, i.e. if the compiler is likely to
11dnl drop unused 'static inline' functions.
12AC_DEFUN([gl_INLINE],
13[
14  AC_REQUIRE([AC_C_INLINE])
15  AC_CACHE_CHECK([whether the compiler generally respects inline],
16    [gl_cv_c_inline_effective],
17    [if test $ac_cv_c_inline = no; then
18       gl_cv_c_inline_effective=no
19     else
20       dnl GCC defines __NO_INLINE__ if not optimizing or if -fno-inline is
21       dnl specified.
22       dnl Use AC_COMPILE_IFELSE here, not AC_EGREP_CPP, because the result
23       dnl depends on optimization flags, which can be in CFLAGS.
24       dnl (AC_EGREP_CPP looks only at the CPPFLAGS.)
25       AC_COMPILE_IFELSE(
26         [AC_LANG_PROGRAM([[]],
27           [[#ifdef __NO_INLINE__
28               #error "inline is not effective"
29             #endif]])],
30         [gl_cv_c_inline_effective=yes],
31         [gl_cv_c_inline_effective=no])
32     fi
33    ])
34  if test $gl_cv_c_inline_effective = yes; then
35    AC_DEFINE([HAVE_INLINE], [1],
36      [Define to 1 if the compiler supports one of the keywords
37       'inline', '__inline__', '__inline' and effectively inlines
38       functions marked as such.])
39  fi
40])
41